Position of HD 45975 (filled circle) compared to instability strips at solar metallicity for β Cephei and SPB stars (Miglio et al. 2007). The domains of instability are shown for computations based on OP or OPAL opacities. The position of the other HgMn stars observed with CoRoT (open squares; Alecian et al. 2009) and Kepler (open triangle; Balona et al. 2011) is also shown. The determination of the parameters for KIC 612 8830 is discussed by Catanzaro et al. (2010).